The principle of 3D display technology is to make a left eye and a right eye of a viewer receive images with slight difference, that is, a left eye image and a right image. The left eye image and right image are merged in a brain, so that depth information of objects in the images can be perceived by the viewer, and stereoscopic vision can be formed.
For an early 3D display device, the viewer needs to wear corresponding 3D glasses. Naked-eye 3D display devices have been improved a lot in recent years. Naked-eye 3D display devices can be mainly divided into two types: a slit grating type 3D display device and a microlens array type 3D display device. Slit grating also refers to parallax barrier, which is generally realized with a switching type liquid crystal screen, a polymer type liquid crystal layer, and a polarizing film. The liquid crystal molecules in the polymer type liquid crystal layer can be rotated through controlling the voltage difference between the electrodes on the upper and lower substrates of the switching type liquid crystal screen, and therefore, opaque stripes (i.e., the parallax barrier) can be formed. In the case that the switching type liquid crystal screen is turned on, under the influence of the parallax barrier, the image for the left eye can be viewed by the left eye, but cannot be viewed by the right eye; the image for the right eye can be viewed by the right eye, but cannot be viewed by the left eye. In the case that the switching type liquid crystal screen is turned off, the parallax barrier cannot occur in a display panel, and therefore, the display device functions as an ordinary 2D display device.
Currently, a parallax barrier type 3D display device generally can only work in portrait mode or in landscape mode, therefore, the 3D display effect is limited.